USE OF A CYSTEINE SYNTHESIZING ENZYME AS SELECTABLE MARKER

摘要

The present invention relates to the use of nucleotide sequences encoding cystathionine gamma-lyases as selectable marker for selection of transformed cells. The invention thus relates to methods for generating host cells transformed with a nucleic acid construct comprising a nucleotide sequence encoding a cystathionine gamma-lyase activity and to method wherein such host cell are cultured under selective conditions for the production of a gene product of interest. For increased stringency of selection, the coding sequence of the cystathionine gamma-lyase selectable marker may be modified to reduce the efficiency of translation of the cystathionine gamma-lyase, and/or the amino acid sequence of the cystathionine gamma-lyase may comprise one or more mutations that reduce the level enzymatic activity of the lyase as compared to its wild type counterpart. The invention further relates to nucleic acid constructs comprising nucleotide sequences encoding cystathionine gamma-lyases as selectable marker and to host cells comprising such nucleic acid constructs.